Martin has served 16 years of a thirty year sentence, for her complicity in the kidnappings and for failing to feed Julie Lejeune and Mélissa Russo, who starved to death because she failed to tell the police.

ITV News' Europe Correspondent Emma Murphy reports from Brussels.

Under Belgian law, criminals can be freed after serving a third of their sentences, as long as they meet certain conditions.

Earlier, Martin's lawyer, Thierry Moreau, told reporters: "She will leave (prison) today, because if we detain her for longer than today, that would mean someone has committed another offence."

Hundreds took to the streets of Brussels earlier this month to protest against Martin's release and demand tougher rules on freeing convicted criminals.

Martin is due to live in the convent in the village of Malonne, 60 km (37 miles) southeast of Brussels and just 30 km from the house where Dutroux kept the girls captive.

The Poor Clares nuns' convent, said it agreed to take her in the spirit of Christian forgiveness.